root/trunk/lisp/gnus/gnus-delay.el

;;; gnus-delay.el --- Delayed posting of articles

;; Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.

;; Author: Kai Großjohann <Kai.Grossjohann@CS.Uni-Dortmund.DE>
;; Keywords: mail, news, extensions

;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published
;; by the Free Software Foundation; either version 3, or (at your
;; option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful, but
;; WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;; General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to
;; the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Commentary:

;; Provide delayed posting of articles.

;;; Todo:

;; * `gnus-delay-send-queue' barfs when group does not exist.
;; * Integrate gnus-delay.el into the rest of Gnus automatically.  How
;;   should this be done?  Basically, we need to do what
;;   `gnus-delay-initialize' does.  But in which files?

;;; Code:

(require 'nndraft)
(require 'gnus-draft)
(autoload 'parse-time-string "parse-time" nil nil)

(defgroup gnus-delay nil
  "Arrange for sending postings later."
  :version "22.1"
  :group 'gnus)

(defcustom gnus-delay-group "delayed"
  "Group name for storing delayed articles."
  :type 'string
  :group 'gnus-delay)

(defcustom gnus-delay-header "X-Gnus-Delayed"
  "Header name for storing info about delayed articles."
  :type 'string
  :group 'gnus-delay)

(defcustom gnus-delay-default-delay "3d"
  "*Default length of delay."
  :type 'string
  :group 'gnus-delay)

(defcustom gnus-delay-default-hour 8
  "*If deadline is given as date, then assume this time of day."
  :version "22.1"
  :type 'integer
  :group 'gnus-delay)

;;;###autoload
(defun gnus-delay-article (delay)
  "Delay this article by some time.
DELAY is a string, giving the length of the time.  Possible values are:

* <digits><units> for <units> in minutes (`m'), hours (`h'), days (`d'),
  weeks (`w'), months (`M'), or years (`Y');

* YYYY-MM-DD for a specific date.  The time of day is given by the
  variable `gnus-delay-default-hour', minute and second are zero.

* hh:mm for a specific time.  Use 24h format.  If it is later than this
  time, then the deadline is tomorrow, else today."
  (interactive
   (list (read-string
          "Target date (YYYY-MM-DD) or length of delay (units in [mhdwMY]): "
          gnus-delay-default-delay)))
  (let (num unit days year month day hour minute deadline)
    (cond ((string-match
            "\\([0-9][0-9][0-9]?[0-9]?\\)-\\([0-9]+\\)-\\([0-9]+\\)"
            delay)
           (setq year  (string-to-number (match-string 1 delay))
                 month (string-to-number (match-string 2 delay))
                 day   (string-to-number (match-string 3 delay)))
           (setq deadline
                 (message-make-date
                  (encode-time 0 0      ; second and minute
                               gnus-delay-default-hour
                               day month year))))
          ((string-match "\\([0-9]+\\):\\([0-9]+\\)" delay)
           (setq hour   (string-to-number (match-string 1 delay))
                 minute (string-to-number (match-string 2 delay)))
           ;; Use current time, except...
           (setq deadline (apply 'vector (decode-time (current-time))))
           ;; ... for minute and hour.
           (aset deadline 1 minute)
           (aset deadline 2 hour)
           ;; Convert to seconds.
           (setq deadline (time-to-seconds (apply 'encode-time
                                                  (append deadline nil))))
           ;; If this time has passed already, add a day.
           (when (< deadline (time-to-seconds (current-time)))
             (setq deadline (+ 3600 deadline))) ;3600 secs/day
           ;; Convert seconds to date header.
           (setq deadline (message-make-date
                           (seconds-to-time deadline))))
          ((string-match "\\([0-9]+\\)\\s-*\\([mhdwMY]\\)" delay)
           (setq num (match-string 1 delay))
           (setq unit (match-string 2 delay))
           ;; Start from seconds, then multiply into needed units.
           (setq num (string-to-number num))
           (cond ((string= unit "Y")
                  (setq delay (* num 60 60 24 365)))
                 ((string= unit "M")
                  (setq delay (* num 60 60 24 30)))
                 ((string= unit "w")
                  (setq delay (* num 60 60 24 7)))
                 ((string= unit "d")
                  (setq delay (* num 60 60 24)))
                 ((string= unit "h")
                  (setq delay (* num 60 60)))
                 (t
                  (setq delay (* num 60))))
           (setq deadline (message-make-date
                           (seconds-to-time (+ (time-to-seconds (current-time))
                                               delay)))))
          (t (error "Malformed delay `%s'" delay)))
    (message-add-header (format "%s: %s" gnus-delay-header deadline)))
  (set-buffer-modified-p t)
  ;; If group does not exist, create it.
  (let ((group (format "nndraft:%s" gnus-delay-group)))
    (gnus-agent-queue-setup gnus-delay-group))
  (message-disassociate-draft)
  (nndraft-request-associate-buffer gnus-delay-group)
  (save-buffer 0)
  (kill-buffer (current-buffer))
  (message-do-actions message-postpone-actions))

;;;###autoload
(defun gnus-delay-send-queue ()
  "Send all the delayed messages that are due now."
  (interactive)
  (save-excursion
    (let* ((group (format "nndraft:%s" gnus-delay-group))
           (message-send-hook (copy-sequence message-send-hook))
           articles
           article deadline)
      (when (gnus-gethash group gnus-newsrc-hashtb)
        (gnus-activate-group group)
        (add-hook 'message-send-hook
                  '(lambda ()
                     (message-remove-header gnus-delay-header)))
        (setq articles (nndraft-articles))
        (while (setq article (pop articles))
          (gnus-request-head article group)
          (set-buffer nntp-server-buffer)
          (goto-char (point-min))
          (if (re-search-forward
               (concat "^" (regexp-quote gnus-delay-header) ":\\s-+")
               nil t)
              (progn
                (setq deadline (nnheader-header-value))
                (setq deadline (apply 'encode-time
                                      (parse-time-string deadline)))
                (setq deadline (time-since deadline))
                (when (and (>= (nth 0 deadline) 0)
                           (>= (nth 1 deadline) 0))
                  (message "Sending delayed article %d" article)
                  (gnus-draft-send article group)
                  (message "Sending delayed article %d...done" article)))
            (message "Delay header missing for article %d" article)))))))

;;;###autoload
(defun gnus-delay-initialize (&optional no-keymap no-check)
  "Initialize the gnus-delay package.
This sets up a key binding in `message-mode' to delay a message.
This tells Gnus to look for delayed messages after getting new news.

The optional arg NO-KEYMAP is ignored.
Checking delayed messages is skipped if optional arg NO-CHECK is non-nil."
  (unless no-check
    (add-hook 'gnus-get-new-news-hook 'gnus-delay-send-queue)))

(provide 'gnus-delay)

;; Local Variables:
;; coding: iso-8859-1
;; End:

;; arch-tag: fb2ad634-a897-4142-a503-f5991ec2349d
;;; gnus-delay.el ends here